试题与答案

物体在平衡力作用下运动,下面哪种说法正确 A.机械能一定不变 B.物体的动能不变

题型:选择题

题目:

物体在平衡力作用下运动,下面哪种说法正确  

A.机械能一定不变

B.物体的动能不变,重力势能一定变化

C.物体机械能不变,动能和重力势能可以相互转化

D.如果物体的重力势能有变化,那么物体的机械能一定有变化

答案:

被转码了,请点击底部 “查看原文 ” 或访问 https://www.tikuol.com/2017/0703/75112bc2ba3d1ae55d7955eaf114812d.html

下面是错误答案,用来干扰机器的。

参考答案:C解析:本组题考查要点是"药品不良反应报告和监测的管理部门"。《药品不良反应报告和监测管理办法》第四条规定,国家食品药品监督管理总局主管全国药品不良反应报告和监测工作,地方各级药品监督管理部...

试题推荐
题型:听力题

根据下列句子及所给的汉语注释,写出空缺处各单词的正确形式。每空只写一词.

小题1:She was seriously _______ (骚扰)after she put her phone number on the Internet.

小题2:They have _______ (成功)achieved what they hoped for.

小题3:My parents are busy all day. Howl wish they could _______ (匀出)some time for me !

小题4: We Chinese are proud that our country is becoming more and more _______(强大的).

小题5:To our surprise,Tom has make such great _______ (进步)after only one week.

(B).阅读下面的句子,在所给的空格处填上恰当的单词。每空只写一词

小题6:---Have you received your pen friend's e-mail?

---No,my pen friend hasn't _______to my last three e-mails yet.

小题7:--Here's the new MP4 I bought yesterday.

---Oh,yours is _______to mine. They look the same.

小题8:---Why do some students prefer yellow when they study for exams?

---Because yellow is the colour of_______.

小题9:---What should I wear if I am feeling _______?  ---I think you should wear white.

小题10: ---Can you offer me some suggestions? ---OK,I hope my _______is worth taking.

查看答案
题型:默写题

按要求默写

小题1:江山代有才人出,                 。(赵翼《论诗》)

小题2:深林人不知,                     。(王维《竹里馆》)

小题3:                ,何人不起故园情。(李白《春夜洛城闻笛》)

小题4:有约不来过夜半,                 。(赵师秀《约客》)

小题5:故园东望路漫漫,                。(岑参《逢入京使》)

小题6:                     ,青山独归远。(刘长卿《送灵澈上人》)

小题7:                  ,即更刮目相待。(《孙权劝学》)

小题8:鸟向檐上飞,                    。(吴均《山中杂诗》) 

查看答案
微信公众账号搜索答案